Tuning fork with simultaneous multiple frequencies



y 1, 1952 R. J. M. c. LANGLOYS 2,601,801

TUNING FORK WITH SIMULTANEOUS MULTIPLE FREQUENCIES Filed Aug. 6, 1947Fla.5 2

Patented July 1, 1952 PATENT OFFICE.

TUNING FORK. WITH 'SIMULTKNEUU 8* MULTIPLE FREQUENUIES RmyaIosephMarieGcile La-ngloys; Saint-019ml,v Seineet.-0ise,, France, assignon to,Society. Etablisscments Herrburgen. .Baris, France, a corporationlof'France Application August 6, 1947*, SerialiNo'. 7.66;,536: In? FranceApril 24, 1945 Section}, PublicLaw 690,1 August8,,1946 BatentexpiresApril 24; 1965' 16 Claims. 1.

The present" invention relates to a; tuningfork of complex' shape whoseexcitation by striki'n'g orbyab'owor" any other means generatessimultaneously" several fundamental, frequencies.

The object" of the invention will become apparent as the following,detailed. description progresses, reference. being had to' theaccompenyingdra'wing; whereini:

Fig. 1" illustratesa standard tuningtfork;

} Figs. 2-8 illustrate various complex-shaped tuning forks" according tothe invention,

Fig. 9 is. a sectional viewof a tuning fork according" to the; inventiontaken' on line' IX"IX ofFi'g: 3, wherein, however; thetunin'g fork ispromdedwith damping means, and.

Figs: I'Oandj'll" are. partial viewszof the tunin fork. shown in Fig; 3'provided with different types-of'fdampingf'means.

Leta standardtuningdork 'i' be. considered first on Fig. 1 comprising aswell. known a pair of tines" arranged" in spaced parallel" alignment.Let another tuning-fork '2 (Fig: 2) be also considered with no" tail asthe firstfork; which a; partof the upper: legs is'replaced by a'fork4*which is identical with fork l. of'Fig; 1.

Ifthe lowertine of the fork" 2' is' struck" in a vertical direction,the". complex shaped tuning fork (lower tine; tail member 3 and doubletine fork 4) will? vibrate as if its upper tine (tail member 3 and fork'4) were. identical to: the

said lower. tine; the. compound fork will'vibrate asv a.- standard.tuning" fork on its normal pitch.

0n the contrary iflthe upper tine ofthe upper fork 4." is struck i avertical. direction, the two tuning, forks [and 4 constituted by thethree A tines will vibrate, generating simultaneouslythe fundamental,corresponding to the upper fork' 4 and the fundamental corresponding tothe lower fork. 2. For in fact" the striking action on the upper tineofv fork t'will not only vibrate the. small" fork but also its tail'portion 3- and consequently the other tuning fork 2. Naturally. it isvnecessary for making the second fork 2' vibrate to adjust its upper leg3 which has been cut for fixing the aforesaid? fork" 4..

According. to the. same process it will be posslble. to build('seeFigure' 3) another complexshapedlfork, 2, 4, 6 with threefrequencies and so on; the final fork will be fitted with a tail tomeetthe service requirements;

The shapes. shown on Figs. 1, 2 and 3 are non rcstrictivait being quitepossible'to have, shapes and designs whichv differ widely'from them, asfor example those shown on Figs: 4and '5'. The compound, orcomplex-shaped" tuning fork ac- 23- the latter being provided with atail 5 corresponding to the tail 5 of Figure 31 As explained for thecompound fork in" Figure 2', the compound fork according to Figured,upon a striking action on" the first fork lvibfatesthe tail part-2 andconsequently the'first compound fork 2- anditstail portion 6" whichmakes the second compound fork 6 to vibrate. second compound forkvibrates the tail portion 2 3"which in its turn makes the-third compoundfork2-3 to vibrate. As any one" of these forks vibrates on itsownfrequency, it can beseen that the compound fork of Figure 4 when made tovibrate generates four fundamental'frequencies i. e. those correspondingto the forks 4, 2, Band 23' respectively. If a-compoundfork generating 5fundamentals is to be" designed; this can be made by replacinga partofthe tine 4' of the fork 4 and'by' fixingto the remainin'gtlnepartanother-smaller standard fork. In a general' way a compound forkgenerating" funds.- mentals=comprises n+l tines;

The" compound forkaccording to Figure 5* is similar to that-shown inFigure 4 and differs onlyfrom the latter in that all its tinesareparallel to each other and bent at'rightangles overthe tail portioni.

The fundamental principle lies in the fact that each fork except thefirstone is constituted by'a complex-fork supporting on one ofits legsacomplex or standard fork.

The various legs of the ensemble can be welded, brazed, or made of oneslngle?piec'e.

The Said plane; whereas the tines 4' and 4" which constitute theconstituent fork 4 lies in a different plane.

The vibrations of the compound forks according to the Figures 2 to donot only generate the fundamentals of the several forks but also thehigher partials which are neglected as being remote from thefundamentals by approximately 3 octaves. If the ratio of thesefrequencies of the upper partials 2, 3, 4 to the frequency of thefundamental is to be increased, the tines of the forks may be providedeither with notches 1, 8, '9 and I!) (Fig. 6), or with hollowed portionsH and [2 (Fig. 7) or with weights such as l3 l4, |5and l-B infEig. 8.

The legs of a complex fork can perfectly be calibrated so that thefrequencies produced are for instance the 1st, 2nd, 3rd, 4th, 5th and6th harmonics of a given fundamental.

The complex fork can thus replace strings in certain musical instrumentssuch as the piano, harpsichord, harp, zither, etc.

, It can replace with advantage the rods and forks used in certainmusical instruments such as the dulcitone, typophone, celesta,Xylophone, glas'schord, etc.

Besides those-forks can be used for all cases for which those variousinstruments instead of generating sounds through the channel of asound-board would produce them through any amplifying system (forinstance: a fork vibrating near a polarized coil transmitting inducedvoltages to the terminals of a pick-up in a radio set, the final sourceof sounds being a loud speaker instead of the sound-board).

- In this order of ideas the complex fork is quite advisable forconstituting the vibrating elements of certain types of electric chimeswith a loud speaker.

Figs. 9 to 11 show a new device for damping the forks described above.According to Fig. 9 which is a section of Figure 3 along lines IXIX eachof the tines 6", 2", 4", 4' of for example the compound fork of Figure 3is in contact with a small strip of felt l8, l8, I8", 18 suspended froma common support 20 by means of strip of cloth l9, I9, l9, l9"' whichacts as a flexible articulation, the said common support being slidablein order to permit the damper to be put in service or to be put out ofaction.

According to Fig. 10 which shows two tines corresponding to any one ofthe partial forks of Figures 2 to 8 a lump of damping material 2| (felt,Wool, etc.) is inserted between the legs 2", 4", of the fork whileaccording to Fig. 11 the damper consists of helical coils 22, 22' madeof wool or any other material wound and fixed upon legs 2", 4" of thefork at appropriatelychosen points.

Naturally the invention of the complex fork is in no way limited to theembodiments shown and described and which were chosen only by way ofexample.

What I claim is:

1. A vibratory complex fork having a supporting reed and two oppositelyvibrating tines secured to said reed, in which one of said tinescomprises a tuning fork, a first tail portion carrying said tuning fork,a vibratory tine fixed to said first tail portion and a second tailportion fixed to said supporting reed.

2. A vibratory complex fork having a supporting reed and two opposedvibratable tines secured to said reed, in which at least one tuning forkis fixed to one of said tines. I

3. A vibratory complex fork having a supporting reed and two opposedvibratable tines secured to said reed, in which at least one tuning forkis secured to one of said tines, said one tuning fork being located in aplane different from that determined by the other tine and thesupporting reed.

4. A vibratory complex fork having a supporting reed and two opposedvibratable tines secured to said reed, in which at least one tuning forkis secured to one of said tines, said one tuning fork being located inthe plane determined by the other tine and the supporting reed.

5. A vibratory complex fork having a supporting reed and two opposedvibratable tines secured to said reed, in which one of said tinescarries at least one tuning fork having two opposed vibratable legs, andin which the other tine and at least one of said legs are provided withmeans for eliminating undesirable harmonics of the fundamentals producedby the vibrations.

6. A vibratory complex fork according to claim 5, wherein said harmoniceliminating means includes notches on said other tine and said one leg,said notches being located near the fixed ends thereof.

7. A vibratory complex fork according to claim 5, wherein said harmoniceliminating means includes masses fixed to the free ends of said othertine and of said one leg.

8. A vibratory complex fork having a supporting reed and a first forkincluding two opposed vibratable members secured to said reed, in whichone of said members carries at least a second tuning fork having twoopposed vibratable members and in which the other member of said firstfork and at least one of the members of said second fork are providedwith damping meansj 9. A vibratory complex fork according to claim 8, inwhich said damping means includes a strip of a damping material freelybearing On its associated member.

10. A vibratory complex fork according to claim 8, in which the dampingmeans is formed by a lump of damping material inserted between the saidother member of said first fork and said one member of said second fork.

11. A vibratory complex fork according to claim 8, in which the dampingmeans is constituted by a helical winding of a damping material on itsassociated member.

12. A vibratory complex fork having a supporting reed and two opposedvibratable tines secured to said reed in which one of said tines has areduced length, and a succession of tuning forks supported on the freeend of said one tine. each fork in said succession except the lasthaving a tine or reduced length carrying the next fork in saidsuccession.

13. A vibratory complex fork comprising a succession of progressivelyshorter tuning forks having each two opposed vibratable tines, all butthe shortest of said forks having one tine shorter than the other and inwhich all but the longest of said tuning forks is carried by the shortertine of the next longer tuning fork.

14. A vibratory complex fork as defined in claim 12, in which each ofsaid forks but the longest extends over the free end of the longer tineof the next longer fork.

15. A vibratory complex fork as defined in claim 12, in which at leastone tuning fork of said succession is located in a plane different fromthat determined by the other tuning forks and the supporting reed.

16. A vibratory complex fork as defined in claim 12. in which all of thetuning forks of said succession and the supporting reed are located in asame plane.

REMY JOSEPH MARIE CECILE LANGLOYS.

REFERENCES CITED The following references are of record in the 10 fileof this patent:

Number 6 UNITED STATES PATENTS Name Date Arkins et a1 July 11, 1871Whitney Apr. 8, 1873 Kitching Oct. 1, 1918 Rusler Dec. 23, 1947Shonnard. Feb. 14, 1950 Roth- Sept. 12, 1950

